Light/dark cycle enhancement and energy consumption of tubular microalgal photobioreactors with discrete double inclined ribs

Abstract

Tubular photobioreactors (PBRs) have a great potential in large-scale biomass cultivation and mixers in tubular PBRs have been intensively investigated to achieve high biomass productivity. However, mixers increase not only biomass yield, but also energy consumption. To evaluate performances on increasing light/dark (L/D) cycles and energy consumption of adding a mixer simultaneously, a new parameter named as efficiency of L/D cycle enhancement is introduced. Discrete double inclined ribs, intensively studied in heat transfer, are introduced to tubular PBRs in this work. The number of ribs in a cross section is discussed. These tubular PBRs are investigated in terms of the flow structure, L/D cycle frequency and efficiency of L/D cycle enhancement by computational fluid dynamics. The numerical results show that the increment of L/D cycle frequency caused by the discrete double inclined ribs is larger than the increment of energy consumption caused by the ribs under a wide range of incident light intensity. In general, the increasing of rib length ratio results in a decrease of efficiency and the PBR with two pairs of ribs performs the best. Based on the general trends, a PBR with two pairs of ribs and of which the rib length ratio is 5 is recommended for further studies.

Keywords

Tubular photobioreactor / Discrete double inclined ribs / Vortexes / Light/dark cycle / Efficiency of light/dark cycle enhancement

References

[1] Abu-Ghosh S, Fixler D, Dubinsky Z, Iluz D. Flashing light in microalgae biotechnology. Bioresour Technol, 2016, 203: 357-363.

[2] Acie FG, Sanchez JA, Grima EM. A model for light distribution and average solar irradiance inside outdoor tubular photobioreactors for the microalgal mass culture. Biotechnol Bioeng, 1997, 55: 701-714.

[3] Acién Fernández FG, Fernández Sevilla JM, Molina Grima E. Photobioreactors for the production of microalgae. Rev Environ Sci Biotechnol, 2013, 12: 131-151.

[4] Cheng W, Huang J, Chen J. Computational fluid dynamics simulation of mixing characteristics and light regime in tubular photobioreactors with novel static mixers. J Chem Technol Biotechnol, 2016

[5] Chisti Y. Biodiesel from microalgae. Trends Biotechnol, 2008, 26: 126-131.

[6] Gao X, Kong B, Vigil RD. Comprehensive computational model for combining fluid hydrodynamics, light transport and biomass growth in a Taylor vortex algal photobioreactor: Lagrangian approach. Bioresour Technol, 2017, 224: 523-530.

[7] Georgianna DR, Mayfield SP. Exploiting diversity and synthetic biology for the production of algal biofuels. Nature, 2012, 488: 329-335.

[8] Gómez-Pérez CA, Espinosa J, Ruiz LCM, Van Boxtel AJB. CFD simulation for reduced energy costs in tubular photobioreactors using wall turbulence promoters. Algal Res, 2015, 12: 1-9.

[9] Gómez-Pérez CA, Oviedo JJE, Ruiz LCM, Van Boxtel AJB. Twisted tubular photobioreactor fluid dynamics evaluation for energy consumption minimization. Algal Res, 2017, 27: 65-72.

[10] Huang J, Li Y, Wan M, . Novel flat-plate photobioreactors for microalgae cultivation with special mixers to promote mixing along the light gradient. Bioresour Technol, 2014, 159: 8-16.

[11] Kreis CT, Le Blay M, Linne C, . Adhesion of Chlamydomonas microalgae to surfaces is switchable by light. Nat Phys, 2018, 14: 45-49.

[12] Li X, Yan H, Meng J, Li Z. Visualization of longitudinal vortex flow in an enhanced heat transfer tube. Exp Therm Fluid Sci, 2007, 31: 601-608.

[13] Luo HP, Al-Dahhan MH. Analyzing and modeling of photobioreactors by combining first principles of physiology and hydrodynamics. Biotechnol Bioeng, 2004, 85: 382-393.

[14] Meng J (2003) Enhanced heat transfer technology of longitudinal vortices based on field-coordination principle and its application. Tsinghua University

[15] Meng J, Liang X, Li Z. Field synergy optimization and enhanced heat transfer by multi-longitudinal vortexes flow in tube. Int J Heat Mass Transf, 2005, 48: 3331-3337.

[16] Moberg AK, Ellem GK, Jameson GJ, Herbertson JG. Simulated cell trajectories in a stratified gas–liquid flow tubular photobioreactor. J Appl Phycol, 2012

[17] Molina E, Fernández J, Acién FG, Chisti Y. Tubular photobioreactor design for algal cultures. J Biotechnol, 2001, 92: 113-131.

[18] Perner-Nochta I, Posten C. Simulations of light intensity variation in photobioreactors. J Biotechnol, 2007, 131: 276-285.

[19] Perner-Nochta I, Lucumi A, Posten C. Photoautotrophic cell and tissue culture in a tubular photobioreactor. Eng Life Sci, 2007, 7: 127-135.

[20] Pruvost J, Legrand J, Legentilhomme P, Doubliez L. Particle image velocimetry investigation of the flow-field of a 3D turbulent annular swirling decaying flow induced by means of a tangential inlet. Exp Fluids, 2000, 29: 291-301.

[21] Pruvost J, Cornet JF, Legrand J. Hydrodynamics influence on light conversion in photobioreactors: an energetically consistent analysis. Chem Eng Sci, 2008, 63: 3679-3694.

[22] Pruvost J, Cornet JF, Le Borgne F, . Theoretical investigation of microalgae culture in the light changing conditions of solar photobioreactor production and comparison with cyanobacteria. Algal Res, 2015, 10: 87-99.

[23] Razzak SA, Hossain MM, Lucky RA, . Integrated CO₂ capture, wastewater treatment and biofuel production by microalgae culturing—a review. Renew Sustain Energy Rev, 2013, 27: 622-653.

[24] Sorokin C, Krauss RW. The effects of light intensity on the growth rates. Plant Physiol, 1958, 33: 109-113.

[25] Suali E, Sarbatly R. Conversion of microalgae to biofuel. Renew Sustain Energy Rev, 2012, 16: 4316-4342.

[26] Wijffels RH, Barbosa MJ. An outlook on microalgal biofuels. Science, 2010, 329: 796-799.

[27] Wu LB, Li Z, Song YZ. Hydrodynamic conditions in designed spiral photobioreactors. Bioresour Technol, 2010, 101: 298-303.

[28] Yang Z, Cheng J, Ye Q, . Decrease in light/dark cycle of microalgal cells with computational fluid dynamics simulation to improve microalgal growth in a raceway pond. Bioresour Technol, 2016, 220: 352-359.

[29] Zhang Q, Wu X, Xue S, . Study of hydrodynamic characteristics in tubular photobioreactors. Bioprocess Biosyst Eng, 2013, 36: 143-150.

[30] Zhang Q, Xue S, Yan C, . Installation of flow deflectors and wing baffles to reduce dead zone and enhance flashing light effect in an open raceway pond. Bioresour Technol, 2015, 198: 150-156.

[31] Zheng N, Liu W, Liu Z, . A numerical study on heat transfer enhancement and the flow structure in a heat exchanger tube with discrete double inclined ribs. Appl Therm Eng, 2015, 90: 232-241.

Funding

National Natural Science Foundation of China(51576075)